The invention relates to a platform mechanism for a stair-lift. A stair-lift generally comprises a rail which is mounted on a stair-case or on an adjacent wall and which carries a carriage with a chair or a platform for a wheel-chair to enable an infirm person to be carried up and down the stairs. If the stairs consist of one straight flight fabrication of the stair-lift is relatively straight forward. If the carriage is to negotiate curves, however, fabrication of the stair-lift becomes more complex and expensive.
Frequently stair-cases consist of a major flight turning through 90 degrees near the upper level through winders or a quarter landing to one or two further steps. In this configuration a straight stair-lift cannot serve the upper landing level directly and it is necessary to accept the greater cost of a curved stair-lift to achieve this.
One solution to the problem is to provide a hinged platform at the upper level. The platform may be hinged up to a parked position in order not to obstruct the stair-case. When the stair-lift is at or near the upper level the platform is swung down to form a bridge. The platform may be operated manually but this is difficult for a person seated on the stair-lift. If the platform is left down when the stair-lift descends it obstructs the stair-case and presents a serious hazard because someone may inadvertently step off the unprotected edge.
The problems can be overcome by providing powered operation for the platform, operated by push-button or automatically. However, the additional motor drive mechanism and control system is expensive. The present invention seeks to provide an improvement.